1. Field of the Invention
This invention relates to improvements in internal combustion engines, and more particularly, to improvements in the carburetor system used for charging a combustible fuel mixture to said engine.
2. Brief Description of the Prior Art
Numerous efforts have been made to improve the efficiency of gasoline fueled internal combustion engines by providing some type of auxiliary air source from which air, in addition to that normally mixed with the fuel by the conventional carburetor, is provided at certain times during operation of the engine. In general, these systems have undertaken to selectively alter the leanness or richness of the combustible gasoline-air mixture at times when the speed of operation of the engine is such that the mixture provided by the carburetor is relatively inefficiently consumed by the engine. It has also usually been a part of the proposal for realizing improved efficiency to provide a valve operatively connected to the accelerator or throttle of the engine, which valve regulates the amount of auxiliary air introduced to the normal fuel-air mixture from the carburetor in correspondence to the degree to which the accelerator is depressed or the throttle opened.
Since gasoline-fueled internal combustion engines have been used to automobiles for powering such vehicles, a wide variety of types of valved air admission systems have been proposed for attachment between the various types of carburetors used down through the years, and the engine intake manifold for providing controlled quantities of supplementary or auxiliary air to the regular fuel-air mixture developed by the carburetor and charged to the intake manifold. An early patent directed to a system of this type was U.S. Pat. No. 1,102,053 to Johnson. In the Johnson structure, hot air was drawn across the exhaust manifold of the engine, and was admitted in selectively controlled quantities through a valve provided between the updraft carburetor and the intake manifold. The valve was manipulated by a hand lever mounted on the steering column of the vehicle so as to control the quantity of hot air admitted through small holes provided adjacent the passageway from the carburetor to the intake manifold. The object of this system was stated to be to break up globules of liquid gasoline passed by the carburetor to the manifold.
Russell U.S. Pat. No. 1,177,831 proposed to provide a horizontally extending spring loaded valve in a position between the carburetor and the engine. The Russell valve admitted variable amounts of auxiliary air in correspondence to the speed of engine operation (that is, the valve was opened to a variable degree in dependence upon the particular speed at which the engine was operated). Russell alleged that this arrangement provided more economical mixtures of fuel.
In Guthrie U.S. Pat. No. 1,201,457, an auxiliary air valve was provided between the updraft carburetor and the intake manifold of the engine for admitting variable and selectively controlled quantities of air to the intake manifold. The air valve thus provided was connected, and operated in correlation to, the spark advance lever used to control the speed of operation of the engine. Here again, the stated object was to provide more efficient fuel mixtures when the engine was operated under heavy loads.
A slightly later patent was U.S. Pat. No. 1,421,135 to Alton. In the Alton system, auxiliary air was admitted to the intake manifold connected to an updraft carburetor. The Alton system included two valves, one operating in response to the variable vacuum developed by the engine during operation, and the other responding to the momentum of fuel passing through the intake manifold to in turn control the force applied to the first valve by the acting vacuum. Alton claimed that this automatic control, governed by these two parameters to which the two valves responded, made the valve more responsive to engine needs in terms of optimum fuel mixture under varying operating conditions. Interestingly, Alton stated that satisfactory results cannot be realized if the suction in the manifold alone is relied upon to control the amount of auxiliary air admitted to the intake manifold. As will be subsequently shown in continuing the review of prior art in this area, this was also the observation arrived at by a very recent patentee of a system of this general type.
In Fisher U.S. Pat. No. 1,516,282, a suction or vacuum operated check valve was provided in an updraft carburetor to admit air at variable quantities and rates to the intake manifold, with this patentee again claiming to achieve greater economy in the use of fuel. Fisher apparently, in contrast to Alton, concluded that the response of the air admitting valve to vacuum created by the operation of the engine was alone sufficient to provide the auxiliary air necessary to improved operation of the engine.
Stepp U.S. Pat. No. 1,761,692 proposed to admit auxiliary air through a large number of apertures between an updraft carburetor and an intake manifold of the internal combustion engine. Again, rather than simply permitting the valve to respond in its opening and closing to vacuum developed by the engine during use, Stepp proposed to open and close the valve in direct response to movement of the engine throttle.
In U.S. Pat. No. 2,078,481 to Chanavier, a linkage was provided between the accelerator pedal and a valve positioned in a conduit for the purpose of providing auxiliary air to the fuel system. Thus, as the accelerator pedal of the engine was depressed, the amount of air introduced to a location between a downdraft carburetor of the two barrel type and an intake manifold would be varied accordingly. According to the patentee, a substantial saving in fuel consumption was realized with this system. Of the same general type of system--that is, supplemental or auxiliary air admitting valves being connected to, and responsive to, accelerator actuation--were the systems shown in Bashford et al. U.S. Pat. No. 2,100,466 and Roberts U.S. Pat. No. 2,884,954.
A recent attempt to improve on the seemingly agreed upon, less than optimum efficiency of carburetion achieved by factory-made carburetors, from the standpoint of overall engine operation and efficiency, is embodied in Cinque U.S. Pat. No. 3,564,580. The Cinque patent is a more complicated system and, in conformity with the concerns of the times, alleges that the system provided not merely improves the efficiency of engine operation and the economy of fuel consumption, but also reduces the pollution attributable to the combustion products from such engines. It is, as previously pointed out, interesting to note that Cinque, in agreement with the statement many years earlier by Alton, as set forth in U.S. Pat. No. 1,421,135, concluded that supplying auxiliary air, purely in response to the vacuum developed by the engine during operation, was not an adequate answer to the proper control of auxiliary air admitted to the carbureted fuel as it passed to the intake manifold.
To meet the need to provide a response different from a pure vacuum actuated response, Cinque provided conduits or passageways for continuously admitting air to a point of introduction to the fuel mixture between the carburetor and the inlet manifold, with these conduits being open and providing air at all times during all phases of operation of the engine. He then further provided another source of auxiliary air which would be responsive to the vacuum developed in the intake manifold during operation of the engine, such control device being a spring loaded check valve which responded to such vacuum. In actuality, both Cinque and Alton provide systems which, in the final analysis, admit variable quantities of air as the engine is varied in its operation, although, as both claim, such variable quantities of air are not directly and purely dependent upon the development of vacuum during engine operation, and transmitted to the involved valve structures via the intake manifold.
I have proposed a system which includes an air valve which is connected by a control linkage to the accelerator of an automobile, and which is actuated in response to the actuation of the accelerator for varying the opening through the air valve to admit supplemental air to a distribution manifold, or air admission ring, positioned between the carburetor and the intake manifold. I have determined now, after considerable usage of that system, that though it effects some improvement in the efficiency of operation of an internal combustion engine used in conjunction with the system, the employment of an air valve of the type there described in response to the actuation of an automobile accelerator actually is a less desirable system than a different specific system which I have found to be highly efficient in use, and to afford a further improvement in the operation of internal combustion engines. My improved system does not employ an air valve actuated from the throttle, nor does it indeed employ any valve, but relies instead upon a constant, highly specifically dimensioned air passageway which admits air in a certain specific pattern to the flow of the fuel-air mixture from a carburetor to the intake manifold of an internal combustion engine.